What is a limitation of decreasing the field of view (FOV)?

Decreasing the field of view (FOV) can indeed lead to an increased chance of aliasing, which is a specific limitation associated with this practice. Aliasing occurs when the spatial frequency of the object being imaged exceeds the Nyquist frequency, resulting in artifacts that can distort or misrepresent the actual anatomy or pathology present in the imaging data.

When the FOV is smaller, the information being captured is concentrated into a smaller area, which can lead to difficulties in accurately depicting structures that are outside the reduced FOV. If the imaging parameters aren’t adjusted appropriately (such as the sampling frequency), portions of the anatomy that fall outside the defined FOV can appear wrapped and produce false images within the FOV.

This stands in contrast to increased spatial resolution or improved signal-to-noise ratio (SNR), both of which can often be seen with a smaller FOV. Increased spatial resolution results from having more pixels dedicated to a smaller area, leading to finer details in the image. Improved SNR can also occur, because a smaller FOV can result in less noise from surrounding tissues relative to the area being imaged. Less anatomical coverage would also be a characteristic of a reduced FOV, but it is not a limitation in the same context